Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Undersea forces from hurricanes may threaten Gulf pipelines

27.05.2010
Hurricanes could snap offshore oil pipelines in the Gulf of Mexico and other hurricane-prone areas, since the storms whip up strong underwater currents, a new study suggests.
These pipelines could crack or rupture unless they are buried or their supporting foundations are built to withstand these hurricane-induced currents. "Major oil leaks from damaged pipelines could have irreversible impacts on the ocean environment," the researchers warn in their study, to be published on 10 June in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).

With the official start of hurricane season approaching on June 1, news reports about the Deep Horizon oil spill that began fouling the Gulf last month have raised questions about how a hurricane might complicate the unfolding disaster.

A hurricane might also create its own spills, the new research indicates. The storms' powerful winds can raise waves 20 meters (66 feet) or more above the ocean surface. But their effects underwater are little known, although signs of seafloor damage have showed up after some hurricanes.

Based on unique measurements taken directly under a powerful hurricane, the new study's calculations are the first to show that hurricanes propel underwater currents with enough oomph to dig up the seabed, potentially creating underwater mudslides and damaging pipes or other equipment resting on the bottom.

At least 50,000 kilometers (31,000 miles) of pipelines reportedly snake across the seafloor of the Gulf of Mexico. Damage to these pipelines can be difficult to detect if it causes only smaller leaks, rather than a catastrophic break, the researchers say. Repairing underwater pipes can cost more than fixing the offshore oil drilling platforms themselves, making it all the more important to prevent damage to pipelines in the first place.
The researchers, at the U.S. Naval Research Laboratory at Stennis Space Center, Mississippi, got an unprecedented view of a hurricane when Hurricane Ivan, a category-4 storm, crossed the Gulf of Mexico in 2004. The eye of the storm passed over a network of sensors on the ocean floor, put in place to monitor currents along the continental shelf in the Gulf.

The research team found that strong currents along the sea floor pushed and pulled on the seabed, scouring its surface. "Usually you only see this in very shallow water, where waves break on the beach, stirring up sand," says David Wang, co-author of the study. "In hurricanes, the much bigger waves can stir up the seafloor all the way down to 90 meters [300 feet]."

Ivan's waves on the surface created powerful currents that dug up the seafloor. Acoustic measurements using sound waves showed that these currents lofted a lot of sediments, which clouded the water up to 25 meters (82 feet) above the seafloor. The team's seafloor sensors tracking the pressure underwater experienced a big increase, as well. This showed that the ground was washed away beneath the sensors, causing them to sink into a lower, higher-pressure zone.

Using a computer model of wave-induced current stresses, the team estimated how powerful currents would need to be for forces they exert at the sea floor to exceed a "critical force" that triggers sediment suspensions and could lead to underwater mudslides.

According to these estimates, hurricanes considerably weaker than Ivan, which was category-4, could still tear up the seafloor, causing significant damage as deep as 90 meters.

The researchers were surprised by how long the destructive currents persisted after Hurricane Ivan passed by. "The stress on the sea floor lasted nearly a week," says Hemantha Wijesekera, lead author of the study. "It doesn't go away, even after the hurricane passes."

The researchers say they're not sure what strengths of forces underwater oil pipelines are built to withstand. However, "hurricane stress is quite large, so the oil industry better pay attention,"

Wijesekera says.

The Office of Naval Research funded this study.

Maria-Jose Vinas | American Geophysical Union
Further information:
http://www.agu.org

More articles from Studies and Analyses:

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>